Physiological Assessment
Physiological testing is available at the Sports Science and Medicine centre at the University of Birmingham
Why do these tests?
The information we gather from physiological testing is used to assess your current fitness levels and to advise you on areas which may need improvement. The coach can prescribe exact training intensities you should be using for each training zone (from recovery through to high intensity/maximal intervals) and further to this, guide you on how to improve your fitness / performance in your event.
Successful training should result in the following changes: blood lactate concentration at any speed / power output should be lower, lactate threshold should occur at higher speeds, and heart rate is lower for a given speed. Repeated testing may help you to monitor progression in training status. As illustrated on the graph below:
What does an assessment involve?
A physiological assessment involves performing a variety of tests on a treadmill and a cycle ergometer. These tests will determine your physiological responses to exercise at submaximal and maximal intensities. During the tests we measure your blood lactate and heart rate response to exercise as well as your oxygen uptake. This data gives us information about your training status, economy and allows us to prescribe training intensities.
What do the tests involve?
Submaximal Step Test
This is a submaximal test to determine your cycling economy, your heart rate and lactate response to increasing exercise intensities. This test consists of 5-7 stages each lasting 3 minutes each and incremental in intensity. The test is continuous, so you will not have a break between stages. During the test we will collect gas samples using an on-line gas analyzer. This will involve you having a mouth piece and nose clip on for 1 ˝ minutes of each stage. We will also take finger prick blood samples to measure blood lactate concentration. You will also be required to wear a simple heart rate monitor strap around your chest to allow us to have a continuous record of your heart rate response throughout the test.
Maximal Test
The purpose of this test is to determine the maximum power output or running speed that you can obtain and your maximum ability to use the oxygen you breathe in to provide energy for working muscles (known as your VO2max). This test will last between approximately 8 - 16 minutes. During this test you will be required to wear the mouth piece and nose clip for gas analysis for approximately the final 5 minutes of the test. A final finger prick sample will be taken at the end of the test.
What can we do with the results?
The results we obtain from the testing include the following;
- VO2max per kg of body weight (ml/kg/min): Maximal ability to use oxygen and provide energy aerobically.
- Heart rate max: The maximum number your heart beats per minute. This is needed to accurately prescribe training intensities based on heart rate. Heart rate gives an indication of the cardiovascular effort that is required to circulate the blood to provide sufficient oxygen (energy) to maintain the set workload. Aerobically trained individuals often have a lower resting heart rate and a lower sub-maximal heart rate at any given workload compared to untrained individuals. This is a result of the aerobic training adaptations that occur as a result of regular exercise. These adaptations include an increased blood volume, an increased contractility of heart and a more capillaries at the muscles which together mean that the heart has to beat fewer times in order to circulate a given volume of blood to deliver the required oxygen to the active muscles.
- Maximal aerobic power (Wmax): Your maximal power output in Watts is taken during the maximal test and is calculated from the last minute of your test. It is a good indicator of how well you can withstand pain and how good your anaerobic power (ability to generate energy without oxygen) and lactate tolerance is because VO2max reaches a maximal value and plateaus in the last few minutes while the power is still increasing.
- Blood Lactate thresholds: When cycling at increasing speeds, the muscles begin to become fatigued long before you reach VO2 max. This leg fatigue (or muscle burning) is due to an accumulation of lactate. There are 2 main increases in blood lactate above resting levels; aerobic threshold and anaerobic threshold. The points at which these increases occur, alongside your heart rate response, are used to prescribe your personalized training intensities. These thresholds are also a good performance indicator for runners, triathletes, and time-trialists.
- Lactate Threshold: This is the point during exercise when blood lactate starts to rise above baseline or resting levels. It is an indicator of aerobic fitness or how well trained you are. Improvements in baseline aerobic fitness will result in this point occurring at higher speeds, or with a shift in the curve to the right.
- Lactate Turnpoint: This is the point at which there is a “sudden and distinct” increase in blood lactate. This occurs when your body can no longer remove as much lactate from the blood as you are producing, which causes the increase. You are not able to continue for a long time after this point as elevated blood lactate levels will lead to fatigue.
- Economy: Economy of movement is measured by how much oxygen is used at any given speed or power output. The less oxygen you require to perform that movement the more economical you are.
For more information and pricing on triathlon testing services, or to make an appointment, contact: Steve